This is the 17626th most frequent Russian word.
у
The Russian word "у" means "at," "near," or "by" and can also denote possession (e.g., "у меня" = "I have").
In this sentence, 'у' indicates possession - 'I have.' It precedes the pronoun 'меня' to signify something in relation to the subject.
У меня есть книга.
I have a book.
Here, 'у' is used to denote proximity or positioning - 'by' the window.
Я стою у окна.
I am standing by the window.
The word 'у' in this sentence indicates from whom the action of asking is directed - 'asked his friend.'